Monitoring of Toktogul Hydro Power System
Stability Monitoring of Toktogul Hydro Power Stations at River Naryn to Prevent Disastrous Aftermath under Seismic Impact
Tech Area / Field
- ENV-MIN/Monitoring and Instrumentation/Environment
- OBS-GEO/Geology/Other Basic Sciences
8 Project completed
Senior Project Manager
Artyukhov A V
Kyrgyz-Russian Slavonic University, Kyrgyzstan, Bishkek
- Institute of Dynamics of the Geosphere, Russia, Moscow
- US Geological Survey, USA, VA, Reston\nIRIS Consortium, USA, DC, Washington\nUniversität Innsbruck / Instutute of Geotechnica and Tunnelling, Austria, Innsbruck\nPolitecnico di Torino, Italy, Torino
Project summaryProject Objective:
Estimate, control and prediction of dam and its bank surroundings state under seismic loading. Development of dam state monitoring technique.
- Analysis of geodynamic and seismic observations for period of Hydro Power Station (HPS) operating, investigation of stress and strain state and possible failures in dam and canyon walls of Toktogul hydrosystem.
- Estimate of dam and its rock surroundings state after seismic loading.
- Distinguishing of potentially dangerous tectonic fracture zones, choice of area for inspection of technico-economical and social criteria.
- Working out of system for comprehensive geomechanical monitoring of dam and rock surroundings state.
- Experimental observations for dam and its rock surroundings strain caused by tectonic movements.
- Conduction of long-term regime observations at HPS, detection of potentially dangerous zones by geophysical methods, getting information on space-time changes of controlled parameters in order to reveal a character of processes triggered off in massif, their patterns and prognostic characteristics.
- Elaboration of methods for estimation of dam state and prediction of its state in future.
One of the primary component of Kyrgyz Republic economic independence is its power complex including series of Toktogul hydroelectric stations on river Naryn. Toktogul Hydro Power Station – the most powerful from those under exploitation - has concrete gravity dam with height of 215 m and water reservoir with volume of 19,5 mlrd cubic meters, which is the biggest hydrotechnic construction over the world.
Constructing of high (more100 m) dams was started at the close of fifties, that was in essence a new tendency in practice of dam construction. Locations of such dams are, as a rule, on mountain currents, most of which are in seismically active regions. Design, construction and exploitation of those objects faced parallel with difficulties caused by uniqueness of such constructions, as well as with necessity to take notice of seismic factor.
Middle Asia and South Kazakhstan are earthquakes prone vast territories. For the century being about 75 events of intensity 8 and more struck that region and quite often they had disastrous consequences in areas populated and cities.
According to the latest map of North Eurasia seismic zoning, region under study belongs to intensity 9 zone at recurrence period 500 years and to zone of intensity 10 and more with recurrence period of 1000 and 500 years. There are revealed large active faults like Talaso-Fergana fault, Eastern and West-Karasu, Kyzkurgan and Shaidan faults in region, some of them are near main constructions of HPS. Slip along faults may be especially dangerous for HPS.
Toktogul HPS is located at deep canyon which is characterized with high level of tectonic stress and interaction of rocks being under stress with dam basement may bring with time to change of concrete dam’s stress state. Such a phenomenon has been already observed at a number of big dams, where it resulted to fracture formation and other troublesome after-effects.
Based on maximum hydrodynamic regimes calculation in HPS downstream in case of destruction of its dam about 600 th. hectares land and 4706 settlements of Fergana Valley with 20 million people population may be flooded. Break wave travels through territory of 4 Republics and may reach Chardary for 75 hours.
Under such conditions a problem of seismic stability of hydro technical constructions as a whole gained in rather actual importance and, therefore, a special attention is to be given to seismic stability and reliable exploitation of high-head dams. Emergency situations at such constructions are inadmissible at all, because their after-effect is too hard. When construction of hydro technical objects and water system extends essentially it becomes necessary to provide acceptance of technically valid and economically effective design solutions as well as to reach high quality of works. It is obvious that we can reach that above all by doing full scale comprehensive investigations.
Organizing and carrying out seismometry observations and well-timed distinguishing of dangerous geodynamical situations and their possible after-effect on such unique objects like Toktogul HPS are of great importance for their safe and long operating. Even under error free design and high quality construction accumulation of failures occur by virtue of ageing processes and irreversible deformations in dam body and its rock basement. In time that may affect on dam stability and require appropriate corrections to regime of hydro system operation.
Monitoring of HPS dam state gains in special actuality to the fall of dam life, when question to last its operation may probably arise. Objective decision on that concern one may obtain only based on results of long-term monitoring which is necessary to start as early as possible.
Data gathered during Toktogul HPS operating are of great interest. Current Project aimed at development of recommendations for safe exploitation of hydro system located at seismically active region. Making research on project and fulfillment of task posed will provide safe condition of Toktogul HPS dam operating in Kyrgyzstan and furnish invaluable experience for world Hydroenergetics.
Project will offer an employment to the scientists and engineers involved into development and production of weapon to let them to transfer their skills to peaceful activity.
Fulfillment of Project will give economic and scientific effect. Besides Project will allow to get new knowledge and make following invaluable contribution:
- To summarize experience of long term operating of Toktogul HPS under high seismic activity conditions.
- To develop new approaches and techniques for monitoring of stability of natural and man-made slopes with underground and ground based constructions which are sides of big dam surroundings and water reservoir banks.
- To develop method of comprehensive instrumental monitoring of stability of canyon walls at Toktogul HPS under seismic load.
- To estimate current state of dam and rock basement bordering it.
- To develop methods of quantitative estimate of dam and its surroundings state.
- To develop methods of prediction of dam state and prevention of disastrous consequences.
Scope of Activity:
Project is aimed at development of method for dam state monitoring, estimation and prediction of stability of dam, its basement and bank surroundings for case when earthquakes strike that region.
Preliminary Work Stage
Work on project includes:
1. Elaboration of Work Plan and Technical Schedule of the Project.
2. Compiling of Inpidual Work Plans by all Participants
3. To determine the priority of each task implementation and cooperation between Project Participants and Participating Institutions.
4. Writing an Agreement with ISTC.
1. To estimate ground motion parameters for Toktogul Hydro System for the period of its operating (to carry out retro – analysis).
2. To fix influence of regional tectonics to Toktogul Hydro System canyon sides (rock basement and bank surroundings) stability.
3. To work out geomechanical model of rock mass holding Toktogul Hydro Power Station.
4. To estimate information and work capacity of existing hardware for dam state monitoring.
5. To develop new approaches and techniques for monitoring of stability of natural and man-made slopes with underground and ground based constructions which are surroundings of big dams and water reservoir banks.
6. To determine essential system configuration for monitoring of dam stability, stability of its basement and bank surroundings and provide it with all hardware and software for data registration and processing.
7. To elaborate Proposal for monitoring system.
8. To purchase necessary hardware and assemble HPS Monitoring System.
9. To organize information gathering and its real time processing.
10. To make analysis of data obtained and compare them with information obtained before to fix changes in Toktogul HPS buildings occurred in period of lack and death of control hardware.
11. To estimate current state of dam, its basement and bank surroundings.
12. To develop method for prediction of Toktogul HPS buildings state and work out recommendations on its safe operating.
The International Science and Technology Center (ISTC) is an intergovernmental organization connecting scientists from Kazakhstan, Armenia, Tajikistan, Kyrgyzstan, and Georgia with their peers and research organizations in the EU, Japan, Republic of Korea, Norway and the United States.
ISTC facilitates international science projects and assists the global scientific and business community to source and engage with CIS and Georgian institutes that develop or possess an excellence of scientific know-how.